Power driven scaffold



April 5, 1938. H P. FISHER POWER DRIVEN SCAFFOLD Filed Jan. 31

INVENTOR daag/ f? E'S/i/ ATTORNEY Patented Apr. 5,1938

UNITED STATES PATENT OFFICE 8 Claims.

My invention relates to the art of scaffolds. More particularly, my invention relates to a power driven scaffold which may be rapidly and efliciently moved both vertically and horizontally to permit repairs, painting, cleaning, etc. of

the sides of buildings, under and alongside of bridges and in other places where like or similar problems exist in whole or. in part.

It is anobject of this invention to provide a scaffold which may be supported from a single line, which scaffold is stable, permitting the opcrator to readily move about on the same as may be required for the above work.

It is an object of this invention to provide safety means obviating liability of the scaffold from falling and consequential damage to both life and property.

It is an object of this invention to provide a scaffold device which may be rapidly moved s horizontally without returning tothe ground, thus permitting efilcient and rapid painting or cleaning of cornices of buildings, under or side structure of bridges and the like.

it is an object of the invention to provide a scaffold which may be moved both vertically and horizontally by a single operator.

It is a further object of the invention to provide an economical, efficient and rapidly moving scaffold which is characterized by simplicity, low cost I and freedom from. adjustments and repairs.

The vabove mentioned general objects of my invention, together with others inherent in the same, are attained by the device illustrated in the following drawing, the same being preferred exemplary forms of embodiment of my invention, throughout which drawing like reference numerals indicate like parts:

Figure 1 is a view in elevation, with parts broken away, of a device embodying my invention;

Fig. 2 is a sectional view of the same, substantially on broken line 2-2 of Figure 1;

Fig. 3 is a fragmentary elevation on broken line 33 of Figure 1;

Fig. 4 is a plan view on broken line 4-4 of Figure 1;

Fig. 5 is a fragmentarydiagrammatic view in elevation of my device in operation on the side of a building, showing the scafiold suspended from. two driven cables to aid in horizontal movement;

Fig. 6 is a. fragmentary diagrammatic view similar to Fig. 5, of a modified form of the invention showing the scaffold suspended from a driven and a dead line or cable to aid in horizontal movement;

Fig. '7 is a detached fragmentary view showing a dead line orcable: and

Fig. 8 is a fragmentary view on a smaller scale showing a modified form of my power driven scaffold.

In the drawing, the platform I0 is preferably surrounded by a relatively low railing ll high enough to protect the operator, but sumciently low so as not to obstruct the building 12 upon which the operator is working. Also a wire mesh screen 13 is preferably provided to prevent articles from falling oil the platform. Guide rods ll are connected with the platform and extend upwardly therefrom and may extend from substantially the center thereof, so that an operator may walk around the platform without interference from obstructions. The upper ends of the guide rods, ll terminate in ring or cable guide I5. The cable guide I5 is positioned a substantial distance, such as five feet, above the platform Ill to aid in providing stability to the platform. Y

The cable drum l6, gear reduction means 11 and electric motor [8 are supported below the platform ill by bracket means It. The weight of such partsso positioned below the platform serves also to aid in providing stability to the device.

- The electric motor I8 is connected by gear reduction means ll with the cable drum I 6. It is preferable to provide a worm type reduction gear between the motor l8 and the cable drum l6 so that the cable drum l6 can not be rotated by the weight of the scaffold and load thereon, but must be driven in either direction, the gear reduction means ll thereby serving as, an emergency brake to prevent the scaffold from falling. The electric motor 18 should preferably be of the reversible type, to rotate cable drum IS in either direction. Electric control means 20 for electric motor [8 is provided at any convenient location.. Electric conductor. means 2| connects the electric motor IS with the control means 2. and said control means is connected with a suitable source of electrical energy (not shown) by means of electrical conductor means '22. Obviously, other power means as compressed air, air

or internal combustion motors may be substituted for the electric motor l8.

In the event that an air supply means is used in painting -or the like, a paint tank 23 may be carried by the platform and an air hose 2| may u connect said tank with a suitable source of air under pressure (not shown).

A brake for the cable drum l8 may comprise a. brake band 25, spring means 26 urging the brake band into braking relation with the cable drum l6 and lever means 21 for releasing the brake. In other words, I employ a brake which is urged by a spring means into braking relation with the cable drum and is released only when the operator exerts a pressure on the lever means A cable 28 has its lower end portion secured to the cable drum I8, which drum may be divided by partition to form cable receiving portions for cables 28 and 3|.

The upper end of said cable 28 may be connected by detachable means, as hook 29, to anydesired support on the cornice of a building l2. When only the cable 28 is used and the drum I6 is rotated in one direction, the cable -28 is wound on drum l8 and the scaffold is raised, and when the drum I8 is rotated in the other direction, cable 28 is payed out and the scaffold lowered. Preferably rollers 38 are provided on the side of the scaifold so that as the same is raised or lowered it will not mar the side of the building or be marred by the building. These rollers 38 also serve as a means on which the scaffold may be trundled on the ground in moving the same from place to place.

The short cable 3| may have its upper end detachably connected with any suitable support on the cornice of the building by means of hook 32 and its lower end may be attached to the cable drum l6 and wound on said cable drum IS in a reverse direction from the cable 28. Whenever the operator is at the top (see Fig. 5) he may attach said short cable 3| to the cornice and bring the lower end through the cable guide l5 and attach the lower end to the drum in such a manner so that as the cable 28 is payed out the cable 3| will be wound on the drum. As the cable 31 is thus wound on the drum simultaneo'usly with the unwinding of the cable 28, the

v scaffold will be moved horizontally with a minimum of vertical movement as indicated in Fig. 5. .T he reafter cable 28 may have its upper end moved andgattached at a different location, so

that theiscaffold may be further moved horizon't ally 'by' winding in the main cable 28 and unwinding the short cable 3|, or so that the scaffold maybe lowered by unwinding of the main cable 28.

In place of the short cable 3| connected to the drum I6, it may be advisable to use the dead line cable 33 shown in Figs. 6 and 7. The upper end of said cable 33 is attached to the building in a manner similar to the attachment of cable 3|. The lower end is attached to the scaffold instead'of to the drum l8 and is preferably attached to the cable guide [5. The scaffold is then supported and moved by the cable 33 as the cable 28 is payed out. The scaffold is thus moved horizontally but with more vertical movement as is indicated by the dotted lines.

In Fig. 8 I show an alternative form of power driven means for operating the scaffold in the nature of a manually operated means which may be employed for moving the scaffold, making it possible to dispense with the motor. This means comprises a worm-31 meshing with a worm wheel 38 on the shaft of the drum Hi. The worm 31 is connected with a shaft 38 which extends upwardly to a suitable location above the platform and is provided with a crank 48 by which it may be driven. The power and speed ratio of the worm 31 and worm gear 38 are such as to enable a man to raise the weight of the scaffold and its load without excessive effort and at the same time provide a reasonably fast vertical speed of the scaffold commensurate with the manual power used for operating the same. Rotating the worm 31 in one direction will raise the scaffold, while rotating said worm 31 in the opposite direction will lower the scaffold.

In the operation of my device, as for example in connection with a building, a cable 28 is attached to the upper part of the building. The cable is passed through the cable guide I5 and the lower end attached to and wound on cable drum IS. The brake is released by depressing lever 21 and the cable drum l6 operated by control means 28. The scaffold may be thus moved vertically. When the scaffold is near the top, the cable 3| or 33 may be used to move the same horizontally. When the scaffold is thus near the top, the operator may readily climb up steps 36 on the guide rods [4 and properly position the cables without aid. It is also preferable to provide another long cable 34 which may be attached to the building and properly positioned by the operator when he is at the top. This cable 34 permits the operator to move the scaffold horizontally when near the ground by detaching cable 28 as the scaffold rests .on the ground, and

attaching cable 34 to the drum l5. Winding up on cable 34 will then enable the operator to reach a different area on the building. Should the cables 28 and 34 be extremely heavy in weight,

the great portion of such weight may be carried dled by one operator with convenience and speed.

Obviously, changes may be made in the forms, dimensions and arrangement of the parts of my invention, without departing from the principle thereof, the above setting forth only preferred forms of embodiment.

I claim:

1. In a power driven suspendedly supported scaffold, a platform on which an operator may walk; weight means carried below said platform and serving as a stabilizing means; upwardly projecting cable guide supporting means positioned substantially centrally of and supported by the platform and affording an unobstructed passageway for an operator on said platform around said cable guide supporting means; a cable guide carried by the upper portion of the cable guide supporting means at a substantial distance above the platform; and a single cable means threaded through said cable guide and operatively connected with the platform, whereby said scaffoid may be supported with stability from a single cable.

2. In a power driven suspendedly supported scaffold, a platform on which an operator may walk; a power driven drum positioned below said platform and also serving as a stabilizing means; upwardly projecting cable guide supporting means positioned substantially centrally of and supported by the platform and affording an unobstructed passageway for an operator on said platform around said cable guide supporting means; a cable guide carried by the upper portion of the cable guide supporting means at a substantial distance above the platform; and a single cable means threaded through said cable guide and operatively connected with said power driven drum, whereby said scaffold may be supported with stability from a single cable.

3. In a power driven suspendedly supported scaffold, a platform on which an operator may walk; cable driving means carried below said platform and also serving as a stabilizing means, said cable driving means comprising an electric motor, a cable drum, and a gear reduction means interconnecting said motor and said drum; upwardly projecting cable guide supporting means positioned substantially centrally of and supported by the platform and afiording an unobstructed passageway for an operator on said platform around said cable guide supporting means; a cable guide carried by the upper portion of the cable guide supporting means at a substantial distance above the platform; and a single cable means threaded through said cable guide and operatively connected with the cable drum, whereby said scaffold may be supported with stability from a single cable.

4. In a power driven suspendedly supported scaffold, a platform; a driven cable drum below said platform; cable means extending around said drum in one direction; other cable means extending around said drum in the other direction; cable guide means connected with said platform and positioned to guide said cables at a position substantially above said platform; and supporting means securing the upper end portions of said cables at spaced apart positions, whereby the scaffold may be horizontally moved with a minimum vertical movement.

5. In a power driven suspendedlysupported scaffold, a platform; a driven cable drum below said platform; a single supporting cable means operatively connected with said drum; cable guide means connected with the platform and positioned to guide said cable at a position substantially above said platform; another single supporting cable having one end portion connected with the scaffold; and supporting means securing the upper end portions of said cables athorizontally spaced apart positions, whereby the scaffold may be horizontally moved as it is supported wholly or in part by each of said single cable supporting means.

6. In a, power driven suspendedly supported scaffold, a platform; a driven cable drum below said platform; a single supporting cable means operatively connected with said drum; cable guide means connected with the platform and positioned to guide said cable at a position substantially above said platform; another single supporting cable having one end portion connected with said cable guide means; and supporting means securing the upper end portions of said cables at horizontally spaced apart positions, whereby the scafiold may be horizontally moved as it is supported wholly or in part by each of said single cable supporting means.

'7. In a device of the class described, a platform; weightmeans carried below said platform; a cable guide connected with the platform and positioned to guide a cable at a position substantially above the platform; a suspendedly supported cable threaded through said guide for supporting said platform; and other suspendedly supported cable means guided by said guide means, said cable means being horizontally supported as respects the first mentioned cable means, whereby the scaffold may be horizontally moved as it is supported wholly or in part by each of said cable supporting means.

8. The method of moving a scaffold horizontally, comprising suspendedly supporting the scaffold from a single cable means; suspendedly supporting the scaffold from another single cable means which is secured to a horizontally positioned support as respects the first mentioned cable means; and releasing the first mentioned cable means.

HARRY P. FISHER. 

